Recently, the general trends in designing electronic devices are toward small size, light weightiness and easy portability. Moreover, with the increasing development of electronic industries, the internal circuitries of the electronic devices are gradually modularized. In other words, plural electronic components are integrated into a single electronic module. For example, a power module is one of the widely-used electronic modules. An example of the power module includes but is not limited to a DC-to-DC converter, a DC-to-AC converter or an AC-to-DC converter. After the electronic components (e.g. capacitors, resistors, inductors, transformers, diodes and transistors) are integrated as a power module, the power module may be installed on a motherboard or a system circuit board.
Nowadays, an embedded package structure is widely adopted because of many advantages such as smaller footprint, lower profile, higher power density and performance, better thermal management, lower electrical noise and mass production. A conventional embedded package structure will be illustrated as follows. In the embedded package structure, an electronic component with at least one conducting terminal is disposed on a first surface of a substrate, and a first insulation layer is disposed on the first surface of the substrate. If necessary, a second insulation layer is disposed on a second surface of the substrate. Consequently, the electronic component is covered by the first insulation layer. For allowing the conducting terminal to be connected with an external circuit, at least one conductive via is formed in the first insulation layer. Consequently, the conducting terminal of the electronic component may be connected with the external circuit through the conductive via.
As mentioned above, for allowing the conducting terminal of the embedded electronic component to be connected with the external circuit, the conductive via is formed in the first insulation layer. During the formation of the conductive via, a cleaning process with the chemical agent is performed after the via hole is drilled. Since copper has excellent resistance to the laser drilling process, the conducting terminal of the electronic component of the embedded package structure is usually made of copper. In other words, the possibility of causing damage of the insulation layer during the laser drilling process will be minimized. Moreover, since copper has excellent resistance to the chemical agent, the possibility of causing corrosion by the chemical agent will be minimized. Moreover, the native oxide layer on the copper surface is easily removed by etching process.
However, since the conducting terminal of the embedded electronic component of the package structure is made of copper, the type of the electronic component is restricted. If the conducting terminal is made of a non-copper metallic material, the electronic component cannot be directly embedded within the package structure. In particular, if the conducting terminal of the electronic component is made of the non-copper metallic material and the electronic component needs to be embedded in the package structure, the conducting terminal of the electronic component should be firstly treated and then covered by a copper layer, e.g. Cu RDL. Currently, Cu RDL is generally carried out in a wafer-level, which shows specific requirements on wafer thickness for safe wafer-handling. Usually, the staring wafer starts from at least 400 μm in thickness to avoid the wafer crack during the wafer processing.
Therefore, there is a need of providing an improved packaging process of an electronic component in order to eliminate the above drawbacks.